An Attack on the LILLE Stream Cipher

Vahid Amin-Ghafari; Mohammad Ali Orumiehchiha; Saeed Rostami

Paper 2023/111

An Attack on the LILLE Stream Cipher

Vahid Amin-Ghafari

, School of Information and Control Engineering, China University of Mining and Technology

Mohammad Ali Orumiehchiha

, Research Center for Developing Advanced Technology

Saeed Rostami

, University of Zanjan

Abstract

A few small-state stream ciphers (SSCs) were proposed for constrained environments. All of the SSCs before the LILLE stream cipher suffered from distinguishing attacks and fast correlation attacks. The designers of LILLE claimed that it is based on the well-studied two-key Even-Mansour scheme and so is resistant to various types of attacks. This paper proposes a distinguishing attack on LILLE, the first attack since 2018. The data and time complexities to attack LILLE-40 are 2^(50.7) and 2^(41.2), respectively. We verified practically our attack on a halved version of LILLE-40. A countermeasure is suggested to strengthen LILLE against the proposed attack. We hope our attack opens the door to more cryptanalyses of LILLE.

Metadata

Available format(s): PDF
Publication info: Preprint.
Keywords: LILLE stream cipher lightweight encryption distinguishing attack time-memory-data trade-off attack cryptography
Contact author(s): vahidaming @ cumt edu cn
orumiehchiha @ rcdat ir
sae rostami @ gmail com
History: 2023-01-30: approved; 2023-01-29: received; See all versions
Short URL: https://ia.cr/2023/111
License: CC BY-NC-ND

BibTeX

@misc{cryptoeprint:2023/111,
      author = {Vahid Amin-Ghafari and Mohammad Ali Orumiehchiha and Saeed Rostami},
      title = {An Attack on the LILLE Stream Cipher},
      howpublished = {Cryptology ePrint Archive, Paper 2023/111},
      year = {2023},
      note = {\url{https://eprint.iacr.org/2023/111}},
      url = {https://eprint.iacr.org/2023/111}
}